interface Radio {
  switchRadio(trigger: boolean) :void

}

interface Battery {
  checkBatteryStatus() :void
}

interface RadioWithBattery extends Radio {
  checkBatteryStatus() :void
}

class Car implements Radio {
  switchRadio(trigger: boolean) {

  }
}

class Cellphone implements RadioWithBattery {
  switchRadio(trigger: boolean) {

  }

  checkBatteryStatus() {

  }
}